Meanwhile, in the schools, the intention is to get the rate of kids that are immune as close to 100% as possible. That will be difficult without deliberately inoculating them, because they will develop herd immunity at about 66% in their population and it won't spread in that population anymore.

In the nuclear reactor analogy, it's as if you put in half the control rods, but only the ones on the left side of the reactor. That might make the left side strongly subcritical, but the right side might still be critical, even if with an even distribution of the same number of rods, the whole reactor would be subcritical.

This plan is not going to work and it will kill millions of people in Britain unless Chloroquine or something else ends up being a silver bullet for treatment.

so what about those who had to suffer to give this herd immunity? If i were a UK citizen, and i got infected, there's a non-zero chance that i will also need a ventilator. Any, even a tiny misstep will cause the numbers to grow beyond the amount of beds available. That i am asked to take this risk is absurd.

Full isolation and quarantine is a more conservative way - for myself at least. Even if the economic damage is severe.